1. Field of the Invention
The present invention relates to a continuous paper folding device (stacker) for use with a printer.
2. Description of the Related Art
In association with high speeds of a computer system in recent years, a printer as an output device in the computer system is required to also have high-speed performance and high reliability, and an electrophotographic printer as a printer capable of meeting this requirement is hopeful. As such an electrophotographic printer widely used at present, a laser beam printer and an LED array printer are known, and both printers of different types are capable of performing high-speed printing.
In the electrophotographic printer such as the laser beam printer or the LED array printer, a photosensitive drum is uniformly charged to have a given polarity at the first time. Then, the photosensitive drum is negatively exposed according to image information to form an electrostatic latent image on the photosensitive drum. The electrostatic latent image is reversely developed by using a toner charged to have the same polarity as that of the photosensitive drum, so that the toner electrostatically adheres to an exposed portion on the photosensitive drum to thereby form a toner image.
Then, the toner image formed on the photosensitive drum is transferred onto a continuous paper or a cut paper usually by means of a transferring corotron in a transfer station. In the printer using the continuous paper, it is necessary to provide a continuous paper folding device which can surely fold the continuous paper after printed and stack the folded paper.
In a conventional continuous paper folding device for use with the printer, a table for receiving the continuous paper is vertically movably provided, and a pair of blade wheels for tapping a perforated portion of the continuous paper are provided on both sides of the table to forcibly fold the continuous paper along perforations thereof and stack the folded paper on the table. The height of the continuous paper stacked on the table is detected by a photosensor. When the height becomes a predetermined value or more, the table is controlled to be lowered. However, such a conventional continuous paper folding device is required to include a driving mechanism for vertically moving the table, causing a complex structure of the device and an increase in cost.
To cope with this problem, it may be considered to provide a continuous paper folding device including a table which is vertically unmovable but is allowed to be drawn to the front side of the device. Further, a paper tapping mechanism formed of rubber may be used to tap the perforated portion of the continuous paper received on the table and stack the folded paper on the table. In the paper tapping mechanism, a pair of timing belts with blades for tapping the paper may be provided on both sides of the table. However, when the table is drawn to take out the paper stacked on the table, the paper may be caught by the blades projecting over the table to cause cutting of the paper or disengagement of the timing belts from pulleys.